What size Low Voltage Disconnect do I need for a 110ah battery?

[pkolbe]

Hi. I'm building out my first system with 2x160watt panels, a crown 12crv110 battery and a TriStar TS-MPPT-45 Charge Controller.
I plan to run a 12v whynter refrigerator and charge my cell phone.
For now, I've opted to use 12v only and try and skip the inverter (til I add more panels and another battery), but I don't know what kind of auto-off/lvd to purchase.
Here are spec sheets for what I have:

crown 12crv110 battery:

https://www.wholesalesolar.com/cms/crown-6crv390-agm-battery-manual-3306454493.pdf

TriStar TS-MPPT-45 Charge Controller:

https://www.wholesalesolar.com/cms/specs-3754145958.3611104.pdf

My understanding is I need something that will cut-off at 12.2v and turn back on after the battery gets above 12.199 AND handle the type of amps the battery will supply.

Also, does anyone know if thare are there any pre-built panels that have multiple places to plug in cigarette-lighter style plugs?
thx a lot,
-peter

[Mike90250]

Welcome. Generally, I would advise your planned system is about 1/4 required size, but maybe your fridge is a super efficient, super expensive model that could work. Any idea what it's consumption is ?

[pkolbe]

It's a whynter 45qt 12vDC/120vAC that I believe will take somewhere around 26.5amphr/day (I'm looking at running it in 90F weaather as a fridge.)

https://1e18z23t25kn1a9twkg87cma-wpengine.netdna-ssl.com/wp-content/uploads/FM-45G-Comsumption-Chart-1.pdf

I'm also considering a size up, the 62qt fridge/freezer at (It's hard to understand since it's both fridge & freezer) 61.5amphr/day

https://1e18z23t25kn1a9twkg87cma-wpengine.netdna-ssl.com/wp-content/uploads/FM-62DZ-Comsumption-Chart-1.pdf

This website suggests both these whynters pull 4.5amps:
/https://expeditionportal.com/buyers-guide-portable-fridge-freezers/

....these numbers are really sobering. Maybe I need to spend more on the fridge to bring down consumption...but of course my intial question is about the lvd/auto-off.
What do you think?

[Mike90250]

So, most of those fridges use a 12/24V inverter compressor, so there are benifits going to a 24V system, namely batteries in series instead of the dread parallel mess.

Since that site rates in 12V Amp hours, it's going to be best to convert fridge and PV to watt hours.

Volts x Amps = watts Watts x Hours = Watt Hours

12V x 4A for 13 hours = 624wh (48w x 13 h = 624)
same fridge running on 24v
24V x 2A 48w again, x 13 hr 624 wh again. When the fridge runs on 24V the amp will be half.

You have to figure your watt hours consumed, against what your battery can store and solar can harvest.

A 200w panel @ 40V would be 5A BUT that panel will only harvest 80% of nameplate, so it's now a 160w panel. For 2 hours = 320wh, and another 3 hours at half power, another 240wh so you get 560wh on a great sunny day from 200w of panels (roughly, varys with clouds, aim, temperature. ) Well short of your needs.